Delhi’s air pollution levels have reached alarming heights, with toxicity levels reportedly 60 times higher than the safe limits recommended by the World Health Organization (WHO). This hazardous smog results from a combination of natural and human-made factors. Here’s the scientific explanation for the phenomenon
Scientific Causes of Smog in Delhi
a. Vehicular Emissions
- Delhi has a massive number of vehicles, contributing significantly to the release of NOx, CO, and unburned hydrocarbons. These pollutants react with sunlight to form secondary particles, worsening smog.
b. Industrial Pollution
- Factories and power plants around the city release large amounts of SO₂ and other harmful gases, which contribute to smog formation.
c. Crop Stubble Burning
- Farmers in nearby states burn agricultural residue to clear their fields, releasing massive amounts of PM2.5 and other pollutants that drift into Delhi due to prevailing winds.
d. Construction Dust
- Ongoing construction activities release fine dust particles into the air, adding to the particulate matter concentration.
e. Temperature Inversion
- During winters, a phenomenon called temperature inversion traps cold air near the surface, preventing pollutants from dispersing into the upper atmosphere. This leads to an accumulation of toxins in the air.
f. Weather Patterns
- Lack of wind and high humidity in winter allow pollutants to remain stagnant, contributing to the formation of smog.